Exotic-Looking Microbes Turn up in Ancient Antarctic Ice

Mickey Mouse, Klingon, porpoise, sphere, and leftover
turkey are nicknames given to objects found in ancient Antarctic ice from
as deep as 1,249 meters beneath Vostok Station.

Updated, July 17 to include links to recent diatom discoveries.

March 13, 1998: Two scientists exploring
a microworld locked in ancient ice have found a wide range of lifeforms
from fungi, algae, and bacteria to a few diatoms - and a few items with
strange shapes.

"We've found some really bizarre things - things that we've never seen before," said Richard Hoover of NASA's Marshall Space Flight Center. Hoover and Dr. S.S. Abyzov of the Russian
Academy of Sciences have been examining
deep ice core samples from the Vostok Station about 1,000 km (620 miles) from the South Pole.

The objects have fanciful names - like Mickey
Mouse and Klingon (right) - based on passing resemblances. Hoover
expects that most will fall into known categories of microorganisms as
he and Abyzov study the images.

"We're
exploring a new world," Hoover said. "Until we get a lot more experience,
we're going to see brand new things all the time."

The ice harboring these finds is as old as 400,000
years, depending on the depth. Russian scientists at the St. Petersburg
Mining Institute in St. Petersburg, Russia, developed the technology for
drilling ice cores without contaminating the samples. Since 1974, they
have worked at Vostok Station, extracting cores from ever greater depths.

In 1996, the Russian Academy of Sciences announced that a large lake of liquid water lies beneath the 3 km-deep glacier at Vostok.

Meanwhile, the ice samples from above the lake's
surface (which has not been breached) are stirring interest in the scientific
community. In the 1970s, Abyzov discovered - and in some cases revived
- microorganisms in ice that conventional wisdom had said was sterile.

Now the discovery
of ice and slush on Europa and mounting evidence
of water on Mars and on our
own Moon are leading scientists to rethink the possibilities of life elsewhere in the universe.

"These are very important questions for future
cosmic research on places like Europa, comets, the Martian ice caps," Abyzov
said of the mysteries in the Antarctic ice.

This "Mickey Mouse" shape (seen at left in the first image) is actually part of a colony of fluffy microbes buried for several thousand years in the Antarctic ice. What appears to be Swiss cheese (in the enlargements) is actually the filter through which the melted ice was drained. Electron beams drilled holes. Each of these images is linked to a large JPG. Please use with the following credit line: NASA/Marshall Space Flight
Center.Hoover and Abyzov are using Marshall's
Environmental Scanning Electron Microscope (ESEM) to examine material found in the ice. Their work is a collaborative effort
between NASA/Marshall and the Institute of Microbiology of the Russian
Academy of Sciences working in collaboration with the St. Petersburg Mining
Institute and the Institute of Arctic and Antarctic Research in St. Petersburg,
Russia.

"This is very useful," Abyzov said, "because we
do not have this equipment in our laboratory. We have scanning electron
microscopes, but without the additional equipment you have."

Richard
Hoover (left) of NASA/Marshall and Dr. S.S. Abyzov of the Institute of
Microbiology (right) check ESEM images of microbes found in ancient Antarctic
ice. The ESEM is visible behind Abyzov (ESEM operator Greg Jerman is partially
visible behind Hoover). This image links to a 1,500x1,082-pixel,
576K JPG. Photo credit: NASA/Marshall Space
Flight Center.As might be expected,
they have found a lot of atmospheric dust and debris, and possibly some
cosmic dust.

"There are some dust particles with unusual spectra,"
Hoover said. "Which may be cosmic dust particles." The ESEM allows the
operator to designate a point on a specimen and then scan with X-rays to
determine what elements are present. The ratios found in some of the dust
particles do not match ratios expected in terrestrial dust grains.

"Mickey Mouse" and other colonies of small microbes
appear to be out of the ordinary. These are fluffy white objects, about
1 micron wide and resembling cotton balls.

"Here's the shocker," said Hoover, pointing at
the ESEM monitor, "these small coccoid bodies are covered with all this
incredible fibrous structure." The filaments appear to be about 30 to 40
nanometers wide (that's about 1/10th a wavelength of visible light).

"It's
difficult for me to say what it is," Abyzov said, "but I tend to agree
that this is biological."

"There are all sorts of microorganisms in the
ice. Some are readily recognizable as cyanobacteria, bacteria, fungi, spores,
pollen grains, and diatoms, but some are not recognizable as anything we've
ever seen before," Hoover said. Many will turn out to be known. It's just
that they look different under the ESEM, which provides details that are
not available through other microscopes.

They have also found a number of large cyanobacteria
with nanobacteria attached.

"What is clearly going on is that when microorganisms
freeze, they shut down and go into this anabiotic state," Hoover explained.
Anabiotic means alive but inactive, like suspended animation. Russian scientists
have been able to revive and culture bacteria, yeast, fungi, and other
microbes found in ice cores.

"One of the things that was really exciting was
that many of the cyanobacteria from 1,243 meters down had lots of antimony,"
Hoover said. The X-ray spectrum showed carbon, oxygen, zinc, silicon, aluminum,
and potassium - all chemicals common to life. But it also showed an abnormal
amount of antimony, a toxic heavy metal.

"It was not just one of these that had it," Hoover
said, "but microorganism after microorganism."

Gregory Jerman, the ESEM operator, noted that the metal content has varied with depth. At some levels the microorganisms show large quantities of antimony, while in others zinc rings the bell.

More unusual shapes found
in the Vostok Station ice resemble a porpoise, Thanksgiving leftovers,
and a sphere. These names will give way to proper scientific names as Hoover
and Abyzov identify them in the coming months. Each of these images is
linked to a 1350x1050 pixel JPG, 280K to 640K in size. Please use with
the following credit line: NASA/Marshall Space Flight Center.

With more than 150 ESEM images and almost as many
spectra recorded, Hoover and Abyzov next go to the Jet Propulsion Laboratory
in Pasadena, California. There, Dr. Ken Nealson will try to extract genetic
material from the microorganisms.

As Hoover talked, another new image appeared on screen.

"It's pretty big," he said of an object that looked
like a porpoise (above) and probably is a protozoan.

"The work of identifying and classifying everything
in the ice will be long and challenging," Hoover said. He compared it to
his own initiation in the world of diatoms where for years everything looked
new until he became familiar with it. Then he could quickly recognize the
rare unusual specimen.

"It's necessary to know what to look for and the
kinds of things you can see," he said.

Like the Klingon's forehead, a wrinkled object resembling a character from Star Trek, or the porpoise. For now some of them just have nicknames, until Hoover, Abyzov, and their colleagues analyze their exciting images and obtain more definitive identifications of these microscopic beasts of the frozen underworld.